Blood Pressure In Hemodialysis Patients Research Articles

Dialysis-associated hypertension treated with Telmisartan--DiaTel: a pilot, placebo-controlled, cross-over, randomized trial.

Treatment of hypertension in hemodialysis (HD) patients is characterised by lack of evidence for both the blood pressure (BP) target goal and the recommended drug class to use. Telmisartan, an Angiotensin receptor blocker (ARB) that is metabolised in the liver and not excreted via HD extracorporeal circuit might be particularly suitable for HD patients. We designed and conducted a randomised, placebo-controlled, double-blind and cross-over trial for treatment of dialysis–associated hypertension with telmisartan 80 mg once daily or placebo on top of standard antihypertensive treatment excluding other Renin-Angiotensin-System (RAS) blockers. In 29 patients after randomization we analysed BP after a treatment period of 8 weeks, while 13 started with telmisartan and 16 with placebo; after 8 weeks 11 continued with telmisartan and 12 with placebo after cross-over, respectively. Patients exhibited a significant reduction of systolic pre-HD BP from 141.9±21.8 before to 131.3±17.3 mmHg after the first treatment period with telmisartan or placebo. However, no average significant influence of telmisartan was observed compared to placebo. The latter may be due to a large inter-individual variability of BP responses reaching from a 40 mmHg decrease under placebo to 40 mmHg increase under telmisartan. Antihypertensive co-medication was changed for clinical reasons in 7 out of 21 patients with no significant difference between telmisartan and placebo groups. Our starting hypothesis, that telmisartan on top of standard therapy lowers systolic office BP in HD patients could not be confirmed. In conclusion, this small trial indicates that testing antihypertensive drug efficacy in HD patients is challenging due to complicated standardization of concomitant medication and other confounding factors, e.g. volume status, salt load and neurohormonal activation, that influence BP control in HD patients.Trial Registration Clinicaltrialsregister.eu 2005-005021-60

Blood pressure in hemodialysis patients after Great East Japan earthquake in Fukushima

Haga, Nobuhiroa,b; Hata, Junyaa,c; Ishibashi, Keia; Nomiya, Masanoria; Takahashi, Norioa; Kojima, Yoshiyukia Author Information

738 Impact of Serum Sodium Lowering on Systolic Blood Pressure in Hemodialysis Patients

Background: Since the procedure of hemodiafiltration (HDF) accompanies large amounts of ultrafiltration and substitution fluid infusion, the effects on body fluid compartments may be different from hemodialysis (HD). We compared serum sodiumand blood pressures between online-HDF and high-flux HD patients. Methods: Thirty-two out of 101 patients on high-flux HD were voluntarily switched to online-HDF. Their pre- and post-dialysis measurements were compared with the remaining 69 high-flux HD patients Results: The online-HDF group had lower pre- and post-dialysis systolic blood pressures compared with the high-flux HD group (pre-dialysis, 136 + 21 vs. 145 + 19 mmHg, P < 0.05; post-dialysis, 129 + 22 vs. 142 + 25 mmHg, P < 0.05). Pre- and post-dialysis serum sodium concentrations were not significantly different between the online-HDF and high-flux HD groups (pre-dialysis, 138 + 2 mEq/L vs. 137 + 3 mEq/L; post-dialysis, 134 + 2 vs. 134 + 2 mEq/L). However, the decrease in serum sodium concentration was larger in the online-HDF compared with the high-flux HD (3.7 vs. 2.5 mEq/L,P < 0.05). As serum sodium concentration decreased after the dialysis session, pre-dialysis systolic blood pressure (r = 0.317, P < 0.005) and pulse pressure (r = 0.324, P = 0.001) were significantly lowered. The serum sodium lowering also positively correlated with post-dialysis systolic blood pressure (r = 0.304, P < 0.005) and pulse pressure (r = 0.299, P < 0.005). Conclusions: Compared with high-flux HD, online-HDF has a larger serum sodium lowering effect. This may contribute to stabilizing both pre- and post-dialysis systolic blood pressures.

Rapid resolution of severe sustained low blood pressure in haemodialysis patients after successful renal transplantation

Low blood pressure occurring in the absence of volume depletion, anti-hypertensive medication, heart failure or cortisol deficiency occurs in ~5-10% of haemodialysis patients, and can result in serious complications. The pathophysiology of this syndrome is poorly understood. We describe eight cases with dialysis-associated hypotension who underwent renal transplantation. Four patients were severely hypotensive with a systolic blood pressure (SBP) <100 mmHg before and during dialysis, and four had a SBP usually <100 mmHg during dialysis, but usually >100 mmHg between sessions. All had donor-specific human leukocyte antigen antibodies. Six patients underwent pre-transplant plasmapheresis, which was curtailed in two because of further falls in blood pressure. Two patients experienced clotting of their arteriovenous fistula. In one patient cryofiltration was used, which was tolerated without severe falls in the BP. The remaining patient, who had hypotension-associated retinal vein thrombosis before transplant, was supported with an epinephrine infusion and did not receive plasmapheresis. Post-transplant, the first patient did not receive pressor therapy and died from bowel ischaemia. The other seven patients were supported with inotropes on critical care. The administration of steroids did not reverse hypotension. The mean pre-treatment SBP was 96 mmHg (range 71-110, SEM 5.0). After inotropes were withdrawn and graft function was established, the mean SBP was 127 mmHg (range 113-149, SEM 4.9) (P < 0.01). Renal transplantation was performed successfully and safely in patients when pressor therapy was used to treat severe dialysis-associated hypotension and, moreover, the blood pressure normalized rapidly after graft function was established.

Does a reduction in dialysate sodium improve blood pressure control in haemodialysis patients?

There has been debate as to the value of lower sodium dialysates to control blood pressure in haemodialysis patients, as sodium is predominantly removed by ultrafiltration. Re-audit of clinical practice following reduction in dialysate sodium concentration. Overall dialysate sodium concentration decreased from 138.9 ± 1.7 to 137.8 ± 1.7 mmol/L (mean ± standard deviation), resulting in a reduction in pre- and post-dialysis mean arterial pressure (MAP) of 4 mmHg (from 100.6 ± 15.6 to 97.1 ± 15.6, P < 0.01 and from 91.7 ± 15.6 to 87.1 ± 14.6, P < 0.001 respectively), yet fewer patients were prescribed antihypertensives (49.6 vs 60.6%), and less antihypertensive medications/patient (mean 0.86 vs 1.05), ultrafiltration requirements (2.8% vs 3.2% body weight, P < 0.001), and symptomatic intradialytic hypotension (0.19 vs 0.28 episodes per week, P < 0.001). A multivariable model showed that for a dialysate sodium of 136 mmol/L, younger patients had higher MAP than older patients (0.35 mmHg lower MAP/year older; but with a dialysate sodium of 140 mmol/L, there was minimal association of MAP with age (0.07 mmHg higher MAP/year older). Change in clinical practice, amounting to a modest reduction in dialysate sodium was associated with a reduction not only in pre- and post-dialysis blood pressures, but also ultrafiltration requirements and symptomatic intradialytic hypotension. However, this effect on blood pressure was most marked for older patients and women, within minimal effects for younger patients, and lesser effects for men, suggesting that dialysate sodium reduction alone may help improve blood pressure control, but requires additional factors such as dietary sodium restriction to be effective in younger male patients.

Plasma sodium and blood pressure in individuals on haemodialysis

To study the relationship between pre-dialysis plasma sodium and blood pressure (BP), we performed an audit of patients who were on stable haemodialysis at St Bartholomew's and The Royal London Hospital from 1 June 2009 to 15 June 2010. There were 651 patients with 7445 dialysis sessions where both plasma biochemistry and BP were measured before haemodialysis. We found a significant association between plasma sodium and both systolic and diastolic BP. A 1 mmol l(-1) increase in plasma sodium was related to 0.65/0.36 mm Hg increase in BP (P<0.001 for both systolic and diastolic BP) after adjusting for potential confounding factors, including weight gain between dialyses and plasma albumin, both of which are crude indices of extracellular fluid volume. A separate analysis excluding individuals who were on BP treatment showed a similar relationship, with a 1-mmol l(-1) increase in plasma sodium associated with 0.82/0.56 mm Hg increase in BP (P<0.001 for both, N=177). These results provide further support for the accumulating evidence that plasma sodium has an important role in regulating BP, which may be independent of extracellular volume. Our findings in conjunction with other evidence suggest that small changes in plasma sodium could be an important mechanism for the beneficial effects of lower dialysate sodium and lower salt intake on BP in haemodialysis patients.

Variability of blood pressure in dialysis patients: a new marker of cardiovascular risk

Hemodialysis patients have a high cardiovascular mortality, and hypertension is the most prevalent treatable risk factor. We aimed to assess the predictive significance of dialysis-to-dialysis variability in blood pressure in hemodialysis patients. We performed a historical cohort study in 1,088 prevalent hemodialysis patients, followed up for 5 years. The risk of cardiovascular death was determined in relation to dialysis-to-dialysis variability in blood pressure, maximum blood pressure and pulse pressure. Variability in blood pressure was a predictor of cardiovascular death (hazard ratio [HR] = 1.242; 95% confidence interval [95% CI], 1.004-1.537; p=0.046). Also age (HR=1.021; 95% CI, 1.011-1.048; p=0.049), diabetes (HR=1.134; 95% CI, 1.128-1.451; p=0.035), creatinine (HR=0.837; 95% CI, 0.717-0.977; p=0.024) and albumin (HR=0.901; 95% CI, 0.821-0.924; p=0.022) influenced mortality. Maximum blood pressure and pulse pressure did not show any effect on cardiovascular death. Dialysis-to-dialysis variability in blood pressure is a predictor of cardiovascular mortality in hemodialysis patients, and blood pressure variability may be used in managing hypertension and predicting outcomes in dialysis patients.

Influences of Dry Weight Adjustment Based on Bioimpedance Analysis on Ambulatory Blood Pressure in Hemodialysis Patients

❙ABSTRACT❙ Background: Hypertension is a common problem for hemodialysis patients and is associated with an increased cardiovascular mortality. We analyzed ambulatory blood pressure (ABP) in hemodialysis patients and investigated if an adjustment of dry weight can be used to control blood pressure. Methods: ABP was measured for twenty-four hours after hemodialysis. A bioimpedance Analysis (BIA) was conducted. Patients were divided into two groups by the edema index. A normohydration (NH) group included patients with the edema index less than 0.40, and an overhydration (OH) group included patients with the edema index 0.40 or more. We accordingly adjusted the dry weight based on BIA results. Results: Thirty-six patients were recruited, comprising twenty-two men and fourteen women. In regard to the ABP, 24-hour systolic and diastolic blood pressures were 140.2 ± 19.7 mm Hg and 79.0 ± 10.6 mm Hg, respectively. There was a significant association between 24-hour systolic blood pressure and the edema index (r = 0.501, p = 0.002). Twenty four-hour systolic blood pressure was significantly different between the NH and OH groups (median value, 132.0 vs. 150.5 mm Hg; p = 0.008). In OH group, after adjustment of the dry weight, the edema index was decreased from 0.411 ± 0.009 to 0.389 ± 0.047 and office systolic blood pressure was also decreased from 144.7 ± 32.7 mm Hg to 125.3 ± 15.4 mm Hg in OH group (p = 0.028 and p = 0.018, respectively). Conclusions: The edema index obtained by the bioimpedance analysis is significantly correlated with 24-hour systolic blood pressure in hemodialysis patients. Also, an adjustment of dry weight can be used to control blood pressure in hemodialysis patients. (J Korean Soc Hypertens 2012;18(4):166-175)

Renalase, a Novel Enzyme Involved in Blood Pressure Regulation, Is Related to Kidney Function but Not to Blood Pressure in Hemodialysis Patients

Renalase, secreted by the kidney, degrades catecholamines and may play a role in the regulation of sympathetic tone and blood pressure. The aim of this study was to assess serum renalase levels in hemodialysis patients and their relationship to blood pressure control, type of antihypertensive therapy and the presence of residual renal function. Results: The mean serum renalase in the study cohort was significantly higher than in the control group (27.53 ± 7.18 vs. 3.86 ± 0.73 µg/ml, p < 0.001). The serum renalase concentration was significantly lower in patients with residual renal function when compared to the anuric patients. The type of hypotensive treatment (β-blockers, ACE inhibitors or AT1 receptor blockers) did not affect renalase levels. There was a significant inverse correlation between the serum renalase and age (r = –0.28, p = 0.023) and residual renal function (r = –0.327, p = 0.001). Renalase was not related to blood pressure, heart rate or hemodialysis vintage. Conclusion: Elevated renalase levels in HD patients may be due to impaired kidney function. Further studies are needed to prove or disprove the possible role of renalase in the pathogenesis of hypertension in patients with kidney diseases.

Assessment of Coronary Blood Flow in Children with Chronic Renal Failure on Regular Hemodialysis

Background: Coronary flow reserve (CFR) reflects the functional capacity of the microcirculation to adapt to blood demand during increased cardiac work. Diminished CFR may account for several symptoms that are often encountered in haemodialysis patients such as chest pain, arrhythmia and hypotension. lschemic heart disease is by far the leading cause of morbidity and mortality in haemodialysis (HD) patients. Sіnce prevention is not easy, early detection of the disease is the key issue.Objectives: Assessment of coronary flow reserve in children with chronic renal failure on regular hemodialy-sis with transthoracic Doppler echocardiography using dipyridamole as and inducer of coronary hyperemia. Methods: Sixty children of matching age and sex were included in this study, 20 healthy children as a control group and 40 children with chronic renal failure on regular haemodialysis. All studied children were subjected complete history taking, thorough clinical examination, laboratory investigations and assessment of coronary flow reserve with transthoracic Doppler echocardiography using dipyridamole as inducer of coronary hyperemia.Results: There was a significant negative correlation between CFR and LVMI, duration of dialysis, serum cholesterol, triglycerides, LDL levels and blood pressure in hemodialysis patients. A significant positive correlation between CFR and serum IIDI. level was found. There was no significant correlation between CFR and different laboratory parameters.Conclusion: CFR is significantly reduced in children with CAF on regular hemodialysis. Control of blood pressure, correction of anemia and hypervolemia, diet management and physical activity are important in the prevention of / decrease in or improving the coronary flow reserve (CFR).

Serum uric acid is associated with high blood pressure in pediatric hemodialysis patients

Serum uric acid (UA) is positively associated with hypertension (HTN). HTN is common in pediatric patients receiving hemodialysis (HD) and peritoneal dialysis (PD). We assessed the relationship between UA and BP in 63 pediatric dialysis patients by measuring pre-treatment UA levels and BP in HD patients and in-center UA levels and blood pressure (BP) in PD patients. UA levels were similar in both groups [6.8 ± 0.2 (HD) vs. 6.5 ± 0.3 (PD), p = 0.6]. Pre-treatment systolic BP percentile was associated with a high UA level [91.9 ± 2.3 (>6.0 mg/dL) vs. 79.3 ± 5.8 mm Hg (≤6.0 mg/dL), p = 0.01] in HD patients only. There was a negative relationship between UA and dialysis vintage (r = -0.31, p = 0.01). In both groups, there was no relationship between UA and Kt/V. In HD patients, fluid overload was unrelated to UA level [4.2 ± 0.6% (≤6.0 mg/dL) vs. 4.3 ± 0.3% (>6.0 mg/dL), p = 0.9]. Moreover, pre-HD treatment systolic BP percentile correlated with UA (beta 0.36, p = 0.02) independent of volume. UA levels were higher in patients receiving anti-hypertensive medications [6.3 ± 0.2 (No Meds] vs 7.0 ± 0.2 (BP Meds) mg/dL, p= 0.01]. Finally, there was no relationship between serum UA and normalized protein catabolic rate (r = 0.14; p = 0.4). In summary, serum UA impacts BP in pediatric HD patients, independent of volume, nutritional and weight status.

The relationship between chronic volume overload and elevated blood pressure in hemodialysis patients: use of bioimpedance provides a different perspective from echocardiography and biomarker methodologies

Chronic volume overload is very frequent in hemodialysis (HD) patients and is directly associated with hypertension, increased arterial stiffness, left ventricular hypertrophy (LVH), heart failure and ultimately with higher mortality and morbidity. One major issue is that presently there are very few comparative studies of the various methods (clinical, bioimpedance, inferior cava vein diameter (ICV) and Brain Natriuretic Peptide (NT-proBNP)) for volume status evaluation and their correlation with cardiovascular disease. In 160 patients treated by chronic HD in our center, euvolemic according to clinical assessment, we performed evaluation of volume status through bioimpedance spectroscopy (BIS), ICV and NT-proBNP, as well as echocardiography, to estimate the left ventricle structure and function. Despite appearing clinically euvolemic, severe fluid overload, as defined by a relative tissue hydration (RTH)--i.e. fluid overload over extracellular water ratio (FO/ECW)--above 15% was found in 25.6% of patients. Four categories of patients were considered according to pre-HD BP and BIS values. Forty-five percent of patients (group A) had a reasonable control of BP and volume (SBP < 150 mmHg and RTH < 15%), 29.3% (group B) were classified as hypertensive (SBP > 150 mmHg and RTH < 15%), 16.7% (group C) had high blood pressure and marked volume expansion, (SBP > 150 mmHg and RTH > 15%), while 9% (group D) had SBP < 150 mmHg despite RTH > 15%. Assuming that BIS is the most accurate and validated method to assess hydration status, we calculated the positive predictive value for ICV-based evaluation--18%, with a sensitivity of 67% and an important proportion of false negative cases (45%). NT-proBNP was even less accurate: PPV of only 26%, with a sensitivity of 60% and a specificity of only 45% and an extremely high proportion of false positive cases (73%). Group A patients had the best cardio-vascular profile: lowest LV mass and NT-proBNP levels. Using multi-frequency body impedance spectroscopy, we found a large group of hypertensive and/or fluid-overloaded patients despite apparently being at "dry weight" on clinical evaluation and a marked discrepancy between clinical appearance and fluid status. Of the 4 different methods, assuming BCM "gold standard", there were major disagreements and discrepancies between the other three methodologies. BCM is a valuable and simple bed-side tool for the correct management of BP and risk stratification in HD patients as it allows for excellent discriminators of more abnormal cardiac and vascular profiles.

Is Systemic Inflammation of Hemodialysis Patients Improved With the Use of Enalapril? Results of a Randomized, Double-Blinded, Placebo-Controlled Clinical Trial

This study compared the effect of enalapril versus placebo on serum tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and C-reactive protein (CRP) in hemodialysis in a randomized, double- blinded, controlled clinical trial. Patients without infection or antiinflammatory drugs were randomly allocated to a study (n = 13, enalapril, 20 mg/day) or control (n = 12, placebo) group; all had arteriovenous fistula. Serum TNF-alpha, IL-6, and CRP were measured at 0, 1, and 3 months. Systolic blood pressure (baseline vs. final) was 151 +/- 25 vs. 135 +/- 19 mm Hg (p < 0.05) in the study group and 154 +/- 21 vs. 144 +/- 27 mm Hg in control group; diastolic blood pressure was 86 +/- 9 vs. 76 +/- 13 and 91 +/- 16 vs. 81 +/- 18 mm Hg, respectively; median (percentiles 25%-75%) IL-6 (baseline vs. final) was 4.2 (3-8) vs. 4.1 (2-9) pg/mL and 6.3 (3-9) vs. 6.7 (3-8) pg/mL; and CRP was 1.9 (1-7) vs. 3.0 (1-12) mg/L and 4.7 (1-16) vs. 3.9 (2-16) mg/L, respectively. TNF-alpha was detected in only two patients. Enalapril significantly reduced blood pressure in hemodialysis patients, but it did not decrease IL-6 and CRP compared with placebo.

Phosphate Levels and Blood Pressure in Incident Hemodialysis Patients: A Longitudinal Study

An elevated serum phosphate level in hemodialysis patients has been associated with mineral deposition in blood vessels. We studied a possible physiologic consequence of hyperphosphatemia by examining the relation between serum phosphate levels and blood pressure in 707 incident hemodialysis patients from 75 clinics who were enrolled in a prospective cohort study. We conducted cross-sectional and longitudinal multiple linear regression analyses, adjusting for demographics, medical history, and laboratory factors. In cross-sectional analyses at baseline, elevated serum phosphate was associated with higher predialysis systolic blood pressure (SBP) and pulse pressure (PP) at the start of dialysis; each 1 mg/dL higher phosphate level was associated with 1.77 mm Hg higher SBP. In multivariable adjusted longitudinal analyses, for each 1 mg/dL higher serum phosphate at baseline, SBP was higher at 3 months, 1.36 mm Hg (P = .005); 6 months, 1.13 mm Hg (P = .035); 12 months, 1.65 mm Hg (P = .008); 18 months, 1.44 mm Hg (P = .031); and 27 months, 2.54 mm Hg (P = .002). PP was higher at 3 months, 0.80 mm Hg (P = .027); 6 months, 0.91 mm Hg (P = .022); 12 months, 1.45 mm Hg (P < .001); 18 months, 1.06 mm Hg (P = .026); and 27 months, 1.37 mm Hg (P = .020). This study suggests that serum phosphate level is strongly and independently associated with blood pressure in hemodialysis patients. The effect of rigorous control of serum phosphate levels on arterial stiffness and blood pressure should be studied in clinical trials.

Weekly Averaged Blood Pressure Is More Important than a Single-Point Blood Pressure Measurement in the Risk Stratification of Dialysis Patients

With regard to monitoring blood pressure in hemodialysis patients, it is important to define clearly the time point at which the blood pressure is measured, because the blood pressure of hemodialysis patients varies with each hemodialysis session as a result of loss of excess fluid. Using weekly averaged blood pressure, 96 hemodialysis patients were studied prospectively for 35 mo. All patients were followed up for cardiovascular events or death from all causes. Pulse weekly averaged blood pressure and age at enrollment were significantly higher and parathyroid hormone level was significantly lower in patients with cardiovascular events compared with those without cardiovascular events; however, none of the components of pre- or postdialysis blood pressure was significantly different between patients with and without cardiovascular events. Pulse weekly averaged blood pressure, prepulse pressure, age, and human atrial natriuretic peptide were significantly higher in patients who died than in survivors. Kaplan-Meier method with a log-rank test demonstrated that survival free rate from cardiovascular events and that of all-cause mortality in patients with pulse weekly averaged blood pressure > or =70 mmHg were significantly lower than those in the remaining patients. One-point measurement of blood pressure is insufficient to evaluate hypertension and prognosis of hemodialysis patients, and weekly averaged blood pressure is a useful marker because of averaging fluctuations of blood pressure during 1 wk. Among components of weekly averaged blood pressure, pulse weekly averaged blood pressure could be a good prognostic marker of the incidence of both cardiovascular events and all-cause mortality in hemodialysis patients.

Blood Pressure and Heart Rate Variability in Patients on Conventional or Sodium-Profiling Hemodialysis

Background. Autonomic nervous system dysfunction and dialysate sodium (Na) concentration are believed to play a role in the pathogenesis of hemodialysis-related hypertension. The present study was undertaken to determine whether increases in blood pressure in hemodialysis patients are associated with changes in heart rate variability (HRV), a measure of the autonomic nervous system function, and long-term exposure to increased dialysate Na concentration. Methods. Baseline clinical, biochemical data and HRV of patients undergoing increased Na profiling dialysis (High-Na, n = 9) and on conventional treatment (Control, n = 11) were compared with those obtained after one year of study. Results. After one year, the mean predialysis systolic blood pressure (SBP) increased in seven patients of the High-Na and in five of the Control group, and decreased or remained unchanged in the remaining subjects. Initial HRV was significantly higher in patients with increased SBP, and it increased further in these patients after one year. At the end of the study, post-dialysis plasma Na, osmolality, and weight gains were significantly higher in the High-Na group. No significant correlation, however, was found between individual changes in intradialytic sodium elimination and the alterations in blood pressure. Conclusion. These data suggest that the dialysate sodium concentration, a most important determinant of interdialytic weight gain and fluid balance, is only partly correlated with long-term changes in blood pressure. An increased blood pressure over time may develop in a subset of hemodialysis patients with higher HRV, suggestive of increased sympathetic activity.

The Association of the Sodium “Setpoint” to Interdialytic Weight Gain and Blood Pressure in Hemodialysis Patients

Hemodialysis patients lack the normal mechanisms to regulate body water volume and osmolality. The dialysis treatment is expected to adequately regulate both body water volume and body Na+ content, which is the primary action determining body water osmolality. Data in subjects with normal renal function indicate that an individual has a specific osmolality value above which thirst is generated and fluid will be ingested. This specific osmolality value or "setpoint" varies among individuals, but is quite reproducible within an individual. It was postulated that hemodialysis patients also may have a Na+ 'setpoint', which if increased by the use of higher dialysate Na+ concentration, might be associated with increased interdialytic weight gain and blood pressure. Monthly laboratory and treatment data were abstracted on 58 hemodialysis patients and included pre- and post-dialysis serum Na+ concentrations, interdialytic weight gain and blood pressure over 9 to 16 months. The Na+ concentrations were averaged to determine the individual Na+ 'setpoint' and the Na+ gradient (Dialysis Na+ concentration - mean Na+ concentration) was determined for each patient. Linear regression analyses showed that there was a statistically significant association between the magnitude of the Na+ gradient and interdialytic weight gain and blood pressure. These data suggest that interdialytic weight gain in individual patients may be associated with the use of dialysate Na+ concentration in excess of the patient's desired Na+ 'setpoint'. More individualization of dialysate Na+ concentration may be indicated.

Dialysis dose and the diagnosis of hypertension in hemodialysis patients

To determine whether simultaneous consideration of pre and postdialysis blood pressure (BP) can improve the prediction of interdialytic ambulatory BP in hemodialysis patients, we analyzed BP obtained before and after dialysis using routine or standardized methods and by self-measurement at home in 104 hemodialysis patients. Evidence for effect modification was tested for several plausible demographic, clinical and laboratory factors. Postdialysis BP when considered jointly with predialysis BP improved the diagnostic performance of standardized dialysis unit BP measurements [receiver operating characteristic (ROC) area under the curve (AUC) 0.91 for joint, 0.85 for prehemodialysis ROC (P=0.01 for difference in AUC)]. A trend to improvement existed in ROC AUC with routine dialysis unit BP measurement [ROC AUC 0.88 for joint, 0.82 for prehemodialysis ROC (P=0.055 for difference in AUC)]. Dialysis dose measured by urea reduction ratio was a strong effect modifier for the determination of hypertension by routine (P=0.012) and standardized (P=0.002) dialysis unit BP measurements. This effect modification was not seen with home BP (P=0.26). Simultaneous consideration of predialysis and postdialysis BPs obtained over 2 weeks can improve the diagnosis of hypertension in hemodialysis patients. Dialysis dose may significantly influence the diagnosis of hypertension when dialysis unit BPs are used.

Influence of sodium profile in preventing complications during hemodialysis

Although a safe procedure, hemodialysis (HD) can cause numerous complications. The objective of this study was to evaluate the incidence of complications during dialysis, interdialytic weight gain, and the predialysis and postdialysis blood pressure in HD patients with and without variable sodium. Patients were observed during 12 HD sessions and those presenting with recurrent hypotension were selected for a step-wise model of variable sodium profiling. A total of 53 patients were evaluated; the mean-SD age was 53.7+/-16.3 years and 22 (41.5%) were male. Of these, 18 (34.0%) were selected to receive variable sodium profiling: the mean (SD) age was 59.9+/-12.6 years, and 10 (55.6%) were female. A significant decline in the occurrence of cramps (p<0.027), in the mean interdialytic weight gain (p<0.009), and a tendency to reduce the number of hypotensive episodes were detected in patients using variable sodium profiling. On the other hand, predialysis systolic blood pressure presented a significant increase (p<0.048). Using variable sodium, there was a statistically significant reduction in cramps and in the mean interdialytic weight gain. There was a significant increase in predialysis systolic pressure. Regarding hypotension episodes, only a tendency toward a reduction in the frequency of hypotension episodes could be detected.

86: Hyperphosphatemia is Independently Associated with Systolic and Pulse Blood Pressure in Hemodialysis Patients

86: Hyperphosphatemia is Independently Associated with Systolic and Pulse Blood Pressure in Hemodialysis Patients